SLUUCJ6 November   2023

 

  1.   1
  2.   BQ76907 Evaluation Module
  3.   Trademarks
  4. 1Features
    1. 1.1 Kit Contents
    2. 1.2 Ordering Information
    3. 1.3 BQ76907 Circuit Module Performance Specification Summary
    4. 1.4 Required Equipment
  5. 2BQ76907 EVM Quick Start Guide
    1. 2.1 Before You Begin
    2. 2.2 Quick Start
  6. 3Battery Management Studio Software
    1. 3.1 System Requirements
    2. 3.2 Installing BQStudio
    3. 3.3 BQ76907 bqz File Installation
    4. 3.4 BQStudio Operation and Registers View
    5. 3.5 Commands
    6. 3.6 Data Memory
      1. 3.6.1 Entering, Saving, and Loading Configuration
    7. 3.7 Command Sequences
  7. 4BQ76907 Circuit Module Use
    1. 4.1 Cell Simulator
    2. 4.2 Evaluating with Load Current
    3. 4.3 Evaluating Charge and Discharge Currents
    4. 4.4 Evaluating with Simulated Current
    5. 4.5 Reducing the Cell Count
    6. 4.6 Connecting Cells
    7. 4.7 Connecting to a Host
    8. 4.8 Hardware Configuration
      1. 4.8.1 Configuration Jumpers
    9. 4.9 Configuration Register Programming
  8. 5BQ76907EVM Circuit Module Physical Construction
    1. 5.1 Board Layout
    2. 5.2 Bill of Materials
    3. 5.3 Schematic

Reducing the Cell Count

For proper operation, the top and bottom cells of the BQ76907 must be used. Cell count can be reduced by shorting the unused cell inputs from the next-to-top down. Cell count can be reduced for basic evaluation by shorting unused cells at the input terminal block. Follow the recommendations in the data sheet for which cells to short. Shorting at the input terminal block works for both operation with the cell simulator and cells, but can have some side effects in transient tests because it parallels the shorted resistors to the cell IC where the capacitor provides a signal path to the used input. See Figure 4-4 for an example of simple reduced cell configuration for 5 cells. For the best evaluation with reduced cells in a transient environment, short the VCx pins at the capacitor and remove the unused input resistor. When using the cell simulator, shorting the unused cell at the terminal block is still required to eliminate the simulated cell voltage. Shorting the cell inputs at the terminal block screw terminals is suggested since it will be apparent if the board is re-used for a different cell count. Table 4-1 shows configuration recommendations for reduced cell count.

Table 4-1 Reducing Cell Count
Unused cell
(numbered from bottom cell 1)
Short cell input terminalsInput resistor to removeReplace capacitor with 0 ohmIC inputs shorted
Cell 6CELL6 to CELL5R7C6VC6 to VC5
Cell 4CELL4 to CELL3R9C8VC4 to VC3
GUID-20220718-SS0I-KCVN-9ZQM-SHQNXK0LSGWK-low.svgFigure 4-4 Example 5 Cell Simple Evaluation Configuration